Pulverizing mill



Feb. 21,1983. G. B. FORBES 1,898,823

PULVERIZING MILL Filed Jan. 5, 1928 I I8 INVENTOR.

\ ATTORNEY Patented Feb. 21, 1933 UNITED STATES PATENT OFFICEoonnonpg-rbmans, or GARFIELD, UTAH, nssmnon 'ro mnnrcw smnmrme AND ammocourm, on NEW YORK, N. Y., a CORPORATION or new JERSEY runvnmzme mm.

Application filed January 5, 1828. Serial No. 244,575.

This inventionrelates to pulverizing mills and more particularly toa'roller mill for 'pulverizing hard materials such as coke, coal,gypsum, limestone, phosphate rock and sim- 5 ilar products.

orable conditions.

Roller mills used with the above mentioned type of materials, must beconstructed to withstand comparatively large forces and are frequentlyused under extremely unfav- For example, the dust caused by the crushingoperation is likely to contaminate the bearings and materially reducethe life thereof. It is desirable therefore to construct the bearings ofsuch form as to exclude dust and to prevent the same from entering theoil or grease which is used for lubricating purposes.

In accordance with the present invention, the rollers are mounted onroller bearings which are formed in such manner as to be substantiallydust tight. The lubricant for the bearing is also protected from dust bybeing held within a. dust tight casing.

This invention further provides for separating .the pulverized materialfrom the coarser particles by means of an upward current of air which ismaintained sufficiently strong to pick up and remove particles of thedesired fineness. Due to the dust tight casing for the roller bearing,the dust laden air may be passed directly over the rollers withoutdanger of contaminating either the hearing or the lubricant.

The invention also consists in certain new and original features ofconstruction and combinations of parts hereinafter set forth andclaimed.

Although the novel features which are believed to be characteristic ofthis invention will be particularly pointed out in the claimsappendedfhereto, the invention itself, as to its objects and'advantages,the mode of 1ts operation and the manner of its organlzation may bebetter understood by referring to the following description taken inconnection with the accompanying drawing forming a part thereof, inwhich Fig. 1 is an elevation partly in section, of a roller pulverizingmill constructed in accordance with this invention; and

Fig. 2 is an enlarged section taken on .the line 22 of Fig. 1 showingthe mounting of the roller.

Like reference characters denote like parts in the several figures ofthe drawing.

In the following description and in the claims parts will be identifiedby specific names for convenience, but they are intended to be asgeneric in their application to similar parts as the art will permit.

Referring more in detail to the drawing, in which a particularembodiment of the invention has been shown for purposes of illustration,the mill is shown as comprising an upper chamber 1 containing thesupports for the rollers to be hereinafter described, and a lowergrinding chamber. 2 into which the material to be pulverized isintroduced. Bull ring 3 is secured in grinding chamber 2 and cooperateswith grinding mullers or rollers 4 for pulverizing the material. Rollers4 are mounted for rotation in housing 5 which are pivotally supportedfrom spider 6 as by horizontal pivots 7. Pivots 7 are eccentricallymounted with respect to rollers 4 whereby the weight of the housing andthe roller tends to swing said rollers outwardly against bull 'ring 3.This tendency is increased due to the centrifugal force caused byturning spider 6. Spider 6 is mounted upon vertical shaft 8 which may besupported in any convenient manner and is rotated from a suitable sourceof power which is indicated as belt pulley 9 connected to said verticalshaft through tapered gears 10.

In the operation of the device shown in Fig. 1, material to bepulverized is introduced into upper chamber 1, between bull ring 3 androller 4, by any suitable means (not shown). Vertical shaft 8 is thenrotated and causes rollers 4 to travel around bull ring 3 and to bethrown thereagainst by centrifugal force and by reason of the eccentricmounting of said rollers about pivot 7.

The material coming between bull ring 3 and rollers 4 is crushed, andthe fine particles are separated therefrom and removed by means of anupward current of air in chamber 1. The air. current ispreferablyregulated by any suitable means and the velocity thereofdetermines the size of the particles that will be picked up andseparated from the ground mass.

The particular construction of roller and bearing therefor is shown morein detail n Fig. 2 and comprises a shaft 15 carried in housing 5 andheld in contact with shoulder 16 of said housing by means of nut 17threaded on the upper end thereof. Roller cones 18 are secured to thelower end of shaft as by means of nut 19. The cones are se arated byspacer 20 and b a plurality of s ims 21 which may be use for urpose ofad ustment. Roller 4 is provi ed with a pair of 15 races 23 suitablyositioned to form, in conneetion with rol ers 24, a bearing. Saidrollers 24 are preferably tapered and are positioned on cones 18 to takeup an end thrust to which the may be subjecte due to the 20 weight of roer 4.

Inner casing 25 is secured to roller 4 as by screws 26 and extendsupwardly about shaft 15 forming a comparatively tight running fittherewith. Outer casing 27 is secured to 25 housing 5 by suitable bolts28 and extends downwardly in overlapping relationship to inner casing25. Casings 27 and 25 are so formed as to provide a space for packingmaterial 30 therebetween. Said packing material is positioned between apair of packing rings 31, against one of which a downward force isexerted by coil spring 32. The packing rings are preferably inwardlytapered in order that the force. exerted by springs 32 will force thepacking tightly against inner casing 25, forming a dust-tight fittherebetween. This pressure also forces the lower packing ring 31against shoulder .32 of said inner casing and forms a dust tight jointat that point.

Lower casing 35 is secured to roller 4 by bolts 36 and completelyencloses the lower bearin together with the lower end of shaft 15. T iscasing servesas a dust tight joint to prevent dust from enterin thebearing and also as a lubricant container for holding grease or oil incontact with said bearing, while inner casing 25 forms a similarprotection and lubricant container for the upper part of the rollerbearing.

By means of the above described construction, roller 4 is freelysupported on anti-friction roller bearings and adapted to rotate aboutshaft 15 as it is passed around bull ring 3. The bearing is freelylubricated by reason of the oil chamber formed by casings 25 and 35 andall dust particles are positively prevented from entering either thebearing or the lubricant by means of casing 35, and the 6 dust-tightjoint between casing 25 and casing 27. It has been found in practicethat rollers mounted as above considerably reduced the power requiredfor operation of the mill, and materially lessened the maintenancecharges. 65 The materials mentioned are given only as 1,aes,eas

pointed out in the annexed claims, it will be understood that variousomissions, substitutions and chan es in the forms and details of thedevice il ustrated and in its operation may be made by those skilled inthe art with: out departing from the spirit of theinvention.

What is claimed is:

1. In combination, a shaft, a rotating member, a bearing supporting saidmember on said shaft, a shield possessing a artially recessed outersurface carried by said member and extending along said shaft in runningen agement therewith, a second shield partia y recessed along its innersurface secured by suitable means to said shaft and extending over saidfirst shield to form a closed (packing chamber, and packing means in saichamber forming a dust seal for said bearing and the lubricant therein.

2. In combination, a shaft a rotating member journalled on said shaft,bearings su porting said member on said shaft, 9. shie d having an outerrecess carried by said member and in runnin engagement with said shaft,a second shie d having an inner recess secured to said shaft by suitablemeans and extendin over said first shield and forming with sai firstshield a closed packing chamber, packing means in said chamber, saidfirst shield. being spaced from said shaft adjacent said member to forma lubricant chamber, said lubricant chamber communicating with saidbearing for lubricating the same, and said packing forming a dust sealfor said bearing and the lubricant therein.

3. In combination, a substantiall cally disposed housin a vertical aharigidly secured therein an extending downwardly therefrom, a rotatinmember journalled on the lower end of said shaft, bearing supportin saidmember on said shaft and forming a t rust bearing therefor, an upwardlyextending shield carried b said member and in running engagement withsaid shaft, a second shield carried by said housing and extendingdownwardly over said first shield, said first and second shields beingsuitably shaped to form a closed packing chamber when in assembleddposition, packing means in' said chamber, sai first shield being spacedfrom said shaft adjacent said member to form a lubricant chamber, athird shield carried by said member and formin a second lubricantchamber enclosing the ower end of said shaft, said lubricant chamberscommunicating with said bearing for lubricating the same, and saidpacking forming a dust seal for said bearing and the lubricant therein.

verti- 4. The combination with a shaft of a grinding roller, bearingssupporting said roller on said shaft, a shield carried by said rollerand in runningengagement with said.

shaft, a second shield extending over said first shield with meansforsecuring same to said shaft, said shields being suitably formed to yielda closed packing chamber, packing means in said chamber, said firstshield being spaced from said shaft adjacent said roller to form alubricant chamber, said lubricating chamber communicating with saidbearing for lubricating the same', and saidpacking forming a dust sealfor said bearing and the lubricant therein.

5. The combination with a substantiall vertically disposed housing, avertical sha t rigidly secured therein and extending downwardlytherefrom, a grinding roller journalled on the lower end of said shaft,antifriction bearings supporting said roller on said shaft and forming athrust bearing for said roller, an upwardly extending shield carried bysaid roller and in running engagement with said shaft, a second shieldcarried by said housing and extending downwardlyover said first shieldand forming with said first shield a closed packing chamber, packingmeans in said chamber, said first shield being spaced from said shaftadjacent said roller to form a lubricant chamber, a third shield carriedby said roller and forming a second lubricant chamber enclosin the lowerend of said shaft, said lubrlcant chambers communicating with saidbearing for lubricating the same, and said packing forming a dust sealfor said bearing and the lubricant therein.

In testimony whereof I have hereunto set 40 my hand.

GORDON B. FORBES.

